So, my check engine light came on yesterday. I took the truck to Advanced Auto Parts and the scanner said the fuel system is too lean. I am hoping it is nothing major but was hoping someone has some info or if it has happened to anyone else. Any possible causes, solutions? Any help is appreciated.

When you added the CAI and exhaust changes did you disconnect the battery for 15-20 minutes and reconnect it.My 2008 screw has had a CAI and true dual exhaust on it for 20,000 miles and no issues.Any time a make a change I do the battery thing I was told it will allow the computer to help compensate for the a/f changes. But here is the link for the Gryphon http://www.dieselpowerchips.com/

Yea usually it takes a cold air intake, exhaust and an edge evo or gryphon to cause a lean code though never heard of an exhaust and intake leaning out the engine that bad alone... maybe somethin else like messed up injectors?
or like shotgun said try unhooking the battery first to reset the computer to see if it gets rid of it and remaps it alone. Cause usually exhaust and intake lean it out just enough then the programmer pushes it over the edge by leaning it excessively unless it's custom tuned of course!